Unit 1 - Challenge Question/Exercise

For this course

• J = perpendicular leg dropped from intersection of L and h.
• opp/hyp = J/h = sin(B) = sin(22 degrees) = 0.374606593
• J = h * 0.374606593 = 39.9 * 0.374606593 = 14.9468031
• K = complementary angle with beta by extending h
• K = 90 – B = 90 -22 = 68 degrees
• M = complementary angle with K
• M = 180 – K = 180 – 68 = 112 degrees
• N = angle to sum triangle angles to 180 degrees
• N = 180 – alpha – M = 180 – 13 – 112 = 55 degrees
• Now we have triangle = angle N, opposite is J, hypotunese is L
• opp/hyp = J / L = sin(n) = 0.819152044
• L = J/0.819152044 = 14.9468031/0.819152044 = 18.2466774
• L = 18.25

Videos of MIT Professor Lewin on these subjects

Taught in 1999.